Adhesive bond strength and compliance for denture soft lining materials.

Statement of problem. Soft lining materials have been found to be more susceptible to microbial adhesion than acrylic resin base materials. Denture hygiene is essential to maintain the serviceability of the denture, and microwave energy has been suggested for denture disinfection. Purpose. The purpose of this study was to determine the effectiveness of microwave energy in the disinfection of a long-term soft lining material. Material and methods. A long-term soft lining material was contaminated with known microorganisms and the reduction of organism counts after test disinfection regimes calculated. The disinfection regimes were microwaving for 5 minutes, leaving dry overnight, and soaking overnight in a dilute sodium hypochlorite solution. The test microorganisms were Candida albicans or Staphylococcus aureus . Results. For both organisms, soaking in sodium hypochlorite reduced the number of viable adherent microorganisms recovered significantly more than exposure to microwave energy, which led to greater reduction than leaving the lining material dry overnight ( p Conclusion. With reference to the tested microorganisms, disinfection of Molloplast-b soft lining material in dilute sodium hypochlorite solution proved to be more effective than exposure to microwave energy, which in turn was more effective than leaving the lining dry overnight. (J Prosthet Dent 1998;79:454-8.)

Use of microwave energy to disinfect a long-term soft lining material contaminated with Candida albicans or Staphylococcus aureus

Evaluation of bond strength of soft relining materials to denture base polymers

Statement of Problem. The clinical properties of resilient denture liners may be influenced by the method by which they are polymerized. Purpose. This in vitro study investigated material property changes of 2 new resilient denture lining materials that represent 2 different curing modes: autopolymerization and conventional laboratory processing. Material and Methods. Two silicone-based liner products were tested; one was allowed to autopolymerize (Tokuyama Soft Relining Paste), and the other was laboratory processed (Luci-Sof). Ninety-six disk-shaped specimens (31 × 10 mm) were fabricated in aluminum ring molds for hardness testing. Sixty bar-shaped specimens (44 × 8.5 × 1.2 mm) were fabricated in aluminum molds for water sorption and resin solubility testing. Shore A hardness was determined directly after specimen fabrication and after 1 day, 1 week, 1 month, 6 months, and 1 year of water storage at 37°C. Water sorption and resin solubility were determined at the same time intervals. Analysis of variance and appropriate t tests were used to determine the effect of immersion duration both within and between the products tested. All statistical testing was performed at α=.05. Results. The hardness values of the laboratory-processed material were consistently greater than those of the autopolymerized material. After 1 week of water storage, the hardness of the autopolymerized specimens stabilized, whereas the hardness of the laboratory-processed specimens increased with immersion duration. Water sorption values for the 2 test products were similar after 6 months and after 1 year of water storage. At 1 month, 6 months, and 1 year, significantly lower resin solubility ( P Conclusion. Within the limitations of this study, the laboratory-processed material was harder than the autopolymerized product and demonstrated greater resin solubility over time. The latter result was not expected. (J Prosthet Dent 2002;88:139-44.)

In vitro hardness, water sorption, and resin solubility of laboratory-processed and autopolymerized long-term resilient denture liners over one year of water storage

Mechanical properties of an experimental denture soft lining material.

Soft linings are compliant, viscoelastic materials used to form all or part of the fit surface of a denture. Their complete function is debatable, but they serve to distribute the forces of mastication more evenly and to absorb energy. Other uses include obturators and maxillo-facial prostheses. This review will cover both the so-called 'permanent' soft-lining materials and temporary soft reline materials, often referred to as tissue conditioners.

P S Wright

Papers

Soft lining materials--a review.